title: Spondyloarthritis: From undifferentiated SpA to ankylosing spondylitis.
authors.affiliation: Rheumatology Department, Hospital General de México, Dr. Balmis 148, México DF 06720, México.
authors.forename: Rubén
authors.initials: R
authors.lastname: Burgos-Vargas
mesh_terms: D005260:Female; D006801:Humans; D008297:Male; D025241:Spondylarthritis / Q000175:diagnosis*